Passage 7.8.4
ὅσα μὲν δὴ Ἀχαιοὶ Μακεδόσιν ἢ στρατιᾷ τῇ Σύρων ἐναντία ἐτάξαντο, φιλίᾳ τῇ πρὸς Ῥωμαίους ἔπραξαν· ἐς δὲ Αἰτωλοὺς ἐκ παλαιοῦ σφισιν ἦν οἰκεῖα ἐγκλήματα. ἐπεὶ δὲ ἡ Νάβιδος ἐν Σπάρτῃ τυραννὶς κατελέλυτο, ἐς πλείστην ὠμότητα ἀνδρὸς ἀφικομένου, τὰ ἐς τοὺς Λακεδαιμονίους αὐτίκα ἐνεπεπτώκει·
Indeed, in all their confrontations arranged against the Macedonians or the Syrian army, the Achaeans acted in friendship with the Romans; but against the Aetolians they had longstanding personal grievances. After the tyranny of Nabis in Sparta had been overthrown—his rule having brought about extreme cruelty—the Achaeans immediately turned their attention toward the Lacedaemonians.